Wildflower is published quarterly by the Wildflower Center. Its content is national in scope with articles about the conservation and use of native plants as well as news from the Wildflower Center. A subscription is provided to Wildflower Center members as a benefit of membership.
How to propagate spring wildflowers
Article and photography by Jane Rogers
PASTEL-GREEN LEAVES UNFOLD, migrating birds chirp and tiny bursts of color dot the woods – spring is returning again! Botanist Dr. William Gambill wrote in "Born in the Spring" of the botanical drama that occurs in heavily wooded country as spring "blotted out the damp and dark of winter and allowed the blessed greenness of reawakening plant life to spread slowly over the land."
Now that I've matured into a native plant enthusiast, I want that greenness of spring in my own woods.
I'm embarrassed to admit that as a beginning gardener I yanked up a yellowish clump of fading trilliums thinking they marred the beauty of my first home. Even a decade later, when I'd learned to love natives, I made mistakes. I over-groomed my new woodland garden and now realize I was even weeding out trillium seedlings!
Now I respect, admire and value each native in my woods and have added hundreds of plants, all grown from seed. Plus, I've finally learned to distinguish a seedling from a weed!
As I've expanded my woodland garden, I've discovered that woodland species are trickier to propagate than most. They often have specific germination requirements, and some (like trilliums) take many years to reach maturity. As I watch woodlands being developed, I understand how protecting and propagating wildflowers is an important conservation effort. It's a win-win – producing more plants and conserving them, too.
FOLLOW THESE GUIDELINES to propagate spring-blooming woodland natives. Visit www.wildflower.org/explore to learn the native range of these plants and for growing requirements.
·Jack-in-the-pulpit (Arisaema triphyllum)
has green or maroon hood-like flowers or
spathes and stalks of red berries. Seeds
mature in late summer or fall to a dull-white.
To plant, wear protective gloves, remove
berry skins, soak seeds, rub away orange
residue and plant 1 inch deep. Single leaf
seedlings form in one year. The same
method is used for green dragon (Arisaema
·Red Buckeye (Aesculus pavia) is a shrubby tree with vibrant-red flowers that attracts hummingbirds. Five to six months after blooming it forms a large, round, shiny brown seed. Promptly gather and store seeds in vermiculite and keep in the refrigerator to over-winter and prevent rodent disturbance. In spring, plant in protected deep containers until established. Later, choose a permanent site since buckeyes have long taproots.
·American beautyberry (Callicarpa americana) shrubs have insignificant pink flowers but spectacular clusters of violet or magenta berries in late summer/fall (and winter in the Deep South). Brown seeds easily germinate. Cuttings root well.
I'll share what I've gleaned from my own trial-and-error experience so you too can multiply spring wildflowers right in your own backyard.
First and foremost, woodland seeds need to be planted as soon as they ripen, while they are fresh. Unlike seeds of prairie natives, if woodland seeds dry out or lack moisture or good contact with the soil, they might not reproduce. Botanists label such seeds as hydrophilic. Many woodland seeds have an oily appendage called an elaiosome that attracts hungry bugs that then bury and plant the seeds. If that specific insect isn't nearby when seeds drop naturally to the forest floor or if the temperature is too warm, seeds can easily perish. Prompt planting by hand dramatically increases the success rate for woodland seeds.
Another thing to consider is that fleshy fruits sometimes contain seeds coated with germination inhibitors – a strange twist of a seed's fate. Luckily, a thorough rinsing might allow the seed to sprout and can mean the difference between a single seedling and a whole patch of green offspring.
Sean Watson, nursery manager for the Wildflower Center, has years of experience propagating a full range of native species. I asked Watson for his advice to gardeners wanting to grow wildflowers.
"Lady Bird Johnson believed that each region's landscape looked its best with native plants. For instance, she felt Texas should look like Texas and not somewhere else. Therefore, we follow her vision of letting the natural landscape show its own beauty, and woodland plants play an important role," says Watson.
Watson shares pointers about the use of rooting hormones, sometimes needed when dividing rhizomes or making cuttings. He says, "We use Dip'N Grow, a liquid concentrate rooting hormone containing IBA [Indole-3-butyric acid] and store it in a refrigerator to keep it fresh. Rootone® powder works too. Both should be replaced every few years," Watson says.
Tip cuttings of american beautyberry [Callicarpa americana] root very easily, says Watson. In the spring and summer, Center horticulturists cut off 4-inch to 6- inch branch tips just below a node and remove two-thirds of the lower leaves. Next, they dip the cut end into Dip'N Grow for a few seconds and plant the branch in a mix of 50 percent perlite and 50 percent vermiculite. Many rhizome divisions and cuttings, however, root easily without any rooting hormone.
When the nursery at the Center propagates from seed, Watson says, "We plant woodland seeds as soon as they ripen, in most cases, such as the seed from the red buckeye (Aesculus pavia). The buckeye is one of the largest of our native seeds and often sprouts in a few weeks. When planting, we use this rule of thumb: Plant a seed as deep as a seed is wide."
WOODLAND NATIVES THRIVE in dappled shade and like moist, well-drained soil with plenty of organic matter. Whether you have a tiny corner or a shaded perennial bed, you can start growing natives and their seeds. It's easy to experiment mixing natives and non-natives if their soil and sunlight requirements match.
To prepare a woodland bed:
· Study which plants thrive in your climate, soil and sunlight conditions.
· In a shaded area, prepare the garden bed ahead of time to allow soil to settle. Amend with rotted leaves, compost or other organic matter to replicate a natural habitat for plants or seeds. Good air circulation is important, but tilling surfaces troublesome dormant weed seeds, so keep a careful eye on weeds and use the least toxic method possible to eradicate them.
· When planting seeds, scratch the soil lightly, scatter seeds, cover with a little dirt, pat gently and replace leaf litter. Water as needed, particularly during dry seasons.
· Transplants and seeds benefit from organic mulch. Shredded leaves help maintain soil fertility, discourage weeds and conserve moisture, so skip raking and allow autumn leaves to remain. Avoid bark chips, which can deplete nitrogen. The newer the chips, the more they can rob the soil of nitrogen.
· Curb the use of leaf blowers as they can disturb ripening seeds or uproot a newly planted division.
·Remove invasive plants and aggressive ground cover. Suppress your desire to overweed but protect seedlings until they can be distinguished from a weed.
As you learn how to harvest and plant mature seeds, being in the right place at the right time is crucial. Here are some general steps to help you succeed with propagating spring natives:
· Watch woodlanders closely to learn their
stages of development. Mark your calendar
when the flower bud opens. In many
cases, a berry or seedpod forms and
ripens four to six weeks after flowering.
Other fruits take months to mature.
Monitor the point where the faded
flower petals were attached because that
is where the pod or fruit will develop.
· Look for color changes and a softening of the pod or berry. Use your fingers to gently feel them soften, as with edible fruits. A few weeks after the fruit forms, peel off the skin of a berry or open a pod as a test. Determine if seeds are the right color as specified in whichever guide you consult for advice on the particular plant.
· If seeds appear ripe, rinse or soak (if required) and plant. Cover with forest litter or leaf mulch. Water as needed, especially during dry spells.
· Most seedlings emerge the following spring – but a few species take two years or more. Plant seeds near the "mother" plant to keep track of them but be careful to avoid overcrowding.
William Cullina wrote in his book "Growing and Propagating Wildflowers" of the sensitivity that wildflower gardening fosters for the richness of life around us. "To catch a glimpse of this churning, odorous symphony, we need turn no further than the nearest puddle or log, and to feel that transcendent shiver of joy that comes from somewhere deep and sacred, we must only open ourselves to the little mysteries abounding within these small microcosms." Observing the fruit and learning the seedripening process will bring your enjoyment of wildflowers to a new level.
Jane Rogers is a nature photographer and garden lecturer from Ohio and volunteers at the Center affiliate, the Ohio Governor's Residence and Heritage Garden.